The power of trance can no longer be disputed, a psychiatrist at Stanford University says. It can ease pain, alter perception, and soothe anxiety.

On one, I want you to do one thing: Look up. On two, do two things: Slowly close your eyes and take a deep breath. On three, do three things: Breathe out, relax your eyes, and let your body float. Imagine you are floating in a bath, a lake, a hot tub, or just floating in space. Each breath is getting deeper and easier.

The patient is 80 years old. She is lying under the bright lights of an operating room at Harvard University’s Beth Israel Deaconess Medical Center, where radiologist Elvira Lang is about to thread a catheter through her arteries. The tiny tube will work its way to one of the woman’s kidneys, where it will block the organ’s blood supply. A surgeon is scheduled to remove the kidney the next day. Embolizing the kidney will help keep the operation simple, safe, and tidy. But the woman is running a fever, and her kidney may be infected. Because she ate earlier in the day, she can’t be given a sedative. What should have been a routine procedure has become an ordeal.

“This is your safe and pleasant place to be,” one of Lang’s associates reads from a laminated card. “You can use it in a sense to play a trick on the doctors. Your body has to be here, but you don’t.”

Lang is one of a growing number of hospital physicians who use hypnosis in addition to anesthesia. With David Spiegel, a professor of psychiatry at Stanford University School of Medicine, she has conducted extensive studies of hypnosis in the operating room, often with dramatic results. By adding hypnosis she can make an operation shorter, less painful, and less dependent on drugs. The hardest part of the procedure is getting other doctors to accept it.

Over the years a number of rigorously controlled studies have proved that hypnosis reduces pain, controls blood pressure, and can even make warts go away. But because very few studies have attempted to find out how it works, most scientists are skeptical of its power. Critics suggest hypnosis is no different from the placebo effect. They both use the power of suggestion to get the mind to control the body; neither is a substitute for medicine.

That skepticism has driven Spiegel and other researchers to take a hard look at what happens in the brain during hypnosis. Trance, they have found, opens a window onto the nature of the imagination. Through it we are beginning to glimpse how the mind distinguishes daydreams from reality.

Spiegel is a second-generation hypnotist. His father, Herbert Spiegel, is a psychiatrist who first used hypnosis as a battlefield surgeon in World War II. In 1943 he even used the technique on himself when he was struck by a mortar from a German tank in Mateur, Tunisia. A steel shell fragment protruded from his ankle, but he managed to tune out the pain.

Hypnotized subjects could resist intense pain for a full minute longer than those who weren’t hypnotized.

Soon after returning home, the elder Spiegel was hired as a professor of combat psychiatry at the School of Military Psychiatry at Mason General Hospital in Brentwood, New York. There he used hypnosis to treat hundreds of returning veterans, becoming ever more convinced of its effectiveness. At the same time, the first clinical studies of hypnosis began to appear. In 1961 psychiatrist Ralph August published a study of 850 women who gave birth under hypnosis. Only 4 percent—34 women—required painkillers. Other studies found that hypnotized subjects could resist intense pain for a full minute longer than those who weren’t hypnotized, and for 30 seconds longer than those who had been given a placebo painkiller.

By the 1960s Herbert Spiegel was teaching clinical hypnosis at Columbia University, and his son was among his students. David Spiegel went on to attend medical school at Harvard and to specialize in psychiatry and clinical hypnosis as his father had. In 1978 the two Spiegels coauthored what became the standard textbook in the field: Trance and Treatment: Clinical Uses of Hypnosis.

Now 62, David Spiegel is tall and a bit disheveled, with his father’s oval face. He listens with the stoic patience of a man who has faced many disbelievers. “Hypnosis has been controversial since the beginning,” he says. “The thing is, it just won’t go away. There’s so much about the phenomenon that’s interesting.” Among researchers in the field, Spiegel says, there are two schools of thought and a growing chasm between them. One school claims that hypnosis fundamentally alters a subject’s state of mind; the other believes that there is nothing radical about it, that all the strange experiences and odd behaviors typically associated with hypnosis can be observed in people who are not actually in a hypnotic trance. Spiegel belongs to the first school, and over the years he has had a running debate with two scientists on the other side: Irving Kirsch, a psychologist at the University of Hull in England, and Stephen Kosslyn, a professor of psychology at Harvard.

Kirsch doesn’t deny that hypnosis can be effective. When he was still practicing clinically, he often used the technique. “With hypnosis you do put people in altered states,” he says. “But you don’t need a trance to do it.” He likes to illustrate the point with a talisman of the hypnotic trade: a pocket watch hanging on a chain. Put your elbow on a table, he says, hold the chain between your thumb and forefinger, and let the weight swing freely. Now, keeping your hand as steady as possible, imagine that the pendulum is moving back and forth parallel to your chest. “Just focus on it moving in that direction, side to side,” he says. “Ignore everything else and imagine it going side to side at its own rhythm.” Once it’s swaying that way (and it inevitably will), imagine it swinging another way—clockwise, say, or toward you and away—just to prove to yourself that it’s not a coincidence. Once again, the weight will obey your mind. This little trick works on even the most skeptical and unhypnotizable of people. You don’t have to enter a trance for your subconscious and your body—in this case, the tiny muscles in your fingers—to respond to suggestion. “I could have hypnotized you and done the same thing, but it wouldn’t have been a result of the hypnosis,” Kirsch says. “It would have been a result of your focusing on moving it in a particular direction.”

Spiegel disagrees. He admits that suggestion alone is a powerful tool but believes that hypnosis magnifies its effects. One of his best-known studies found that when subjects were hypnotized and given suggestions, their brain-wave patterns changed. In another of Spiegel’s studies, people under hypnosis were told their forearms were numb, then given light electrical shocks to the wrists. They didn’t flinch or respond in any way, and their brain waves resembled those of people who experienced a much weaker shock.

To Kirsch, this still wasn’t enough to prove the power of trance, but Stephen Kosslyn was beginning to wonder. Kosslyn is an exceedingly polite man with a gray beard and perpetually raised eyebrows. The hypnosis literature is rife with examples of subjects aping what they believe is hypnotic behavior, he says. This “demand effect” is exactly what makes placebos so effective. As for the brain-wave study, other events in the lab—such as interaction with the investigators—could have caused the shift in the subjects’ state of mind. “Is it just playacting?” Kosslyn wondered when he first saw Spiegel’s data. “Or is there something really going on in the brain?”

To find out, Spiegel and Kosslyn collaborated on a study that focused on a part of the brain that is well understood: the fusiform circuit. Part of the occipital lobe, the circuit has been found to process the perception of color. Neuroscientists zeroed in on it by placing subjects in a positron-emission tomography (PET) scanner to measure blood flow in the brain while having them look at cards with color rectangles. Spiegel and Kosslyn wanted to see if subjects could set off the same circuit by visualizing color while they were under hypnosis.

The first step was to find the right study subjects. Only a small fraction of the population—known as highs in hypnosis circles—can enter a deep trance, just as only a few people cannot be hypnotized at all. The rest of us fall on a spectrum in between. Spiegel and Kosslyn selected eight people from a pool of 125 possible subjects; then Kosslyn’s team ran the experiment at Massachusetts General Hospital in Boston. As in previous studies, subjects were put inside a PET scanner and shown a slide with color rectangles, and their brain activity was mapped. Then they were shown a black-and-white slide and told to imagine its having a color. Both tasks were repeated while under hypnosis.

When they simply imagined the colors, only the right hemisphere’s fusiform circuit lit up. But when they were asked to picture the colors while hypnotized, the brains of these subjects responded the same way they did when they actually saw the colors: Both left and right fusiform circuits lit up. Under hypnosis, imagination seemed to take on the quality of a hallucination.

When highly hypnotizable subjects were asked to visualize colors, their brains responded just as if they actually were looking at them.

Kosslyn is not currently involved in ongoing hypnosis research, but this finding was recently replicated and extended by two of Kirsch’s colleagues, Giuliana Mazzoni and Anna­lena Venneri, who reported preliminary results at the American Psychological Association meeting in the summer of 2008. Using fMRI to image brain activity, the researchers found that when highly hypnotizable subjects were asked to visualize the colors, their brains responded just as if they were actually looking at them. So-called lows—people who do not hypnotize easily—did not show the same brain activity. “We still cannot claim that this is an altered state of consciousness,” Mazzoni says. “But I’m inclined to think that highly hypnotizable people have unique skills.”

“I’m absolutely convinced now that hypnosis can boost what mental imagery does,” Kosslyn says. But Kirsch remains skeptical. The color experiments demonstrate that people “are really experiencing the effects of hypnotic suggestion,” Kirsch says, but not necessarily that they enter a trance.

To Kosslyn, this line of work shows how the brain distinguishes between imagination and perception. The right side of the brain processes specific examples of things, while the left side processes more general concepts and categories. The left side knows that Spot is a dog, for instance, while the right side knows that the dog is Spot. That is why, when we imagine a particular color, the right side of the brain lights up but the left side is left cold: The details of the daydream may seem real, but they don’t apply to a larger reality.

“The realms of imagination and perception are not entirely distinct,” Spiegel says. “This goes back to philosophers as far as Kant. What we take as reality is our processing of perceptual input.” We make assumptions about what’s real from small cues that are far from the complete picture. If you are expecting to meet a friend at a restaurant and a stranger comes in with the same jacket and hair, you might call out your friend’s name, but as soon as you see the face your mistake will be obvious. “Rather than passively accepting perception, we set up a competition between imagination and perception,” Spiegel says. “Imagination can alter perception—in a sense it always does. But we’re not aware of it.” Under hypnosis, that distinction breaks down.

Kosslyn believes that hypnosis allows the body to tap into hidden reserves. He compares its effect to that of breaking a world record in sports: It changes our sense of the possible. “For years and years and years, no one could run a mile in under four minutes,” he says. “It was like the sound barrier—people thought that limbs would start falling off.” Yet only six weeks after the record was finally broken, by British runner Roger Bannister in 1954, it was broken again by another runner. “Nowadays 40-year-olds can do it,” Kosslyn says. Hypnosis may have the same effect. “It shifts what I call the assumed norm. It can play the part that Roger Bannister did in the four-minute mile.”

Spiegel is a clinician first. The whys of hypnosis aren’t as important, he believes, as that doctors recognize its power and start to use it. To that end, he and Lang put the technique to the test in the operating room. In 1995 they took 241 patients slated for vascular or kidney surgery and divided them into three groups. One group received standard care; another received standard care with an “empathic care provider”; and the third received standard care, an empathic care provider, and hypnosis. During the operation, the patients lay with their heads behind an opaque, soundproof barrier so surgeons couldn’t tell what care they were receiving. Every 15 minutes the patients were asked to rate their level of anxiety and pain. They were also hooked up to an IV and given as much painkilling medication as they wanted.

The results of the study were published in The Lancet. On average, Spiegel and Lang found, the hypnotized subjects used less medication, experienced less pain, and felt far less anxiety than the other two groups. Patients who weren’t hypnotized felt more pain over time regardless of how much medication they received; those who were hypnotized stayed equally comfortable throughout the surgery. Operations on hypnotized patients averaged 17 minutes shorter than those of other patients, and the cost of a standard radio­logical procedure fell from $638 to $300.

Lang has since bolstered those findings with a trial conducted among 200 patients who underwent a breast biopsy or lumpectomy for breast cancer. Patients were assigned either to routine anesthesia plus “nondirective empathic listening” or to a 15-minute pre­surgery hypnosis session that suggested pleasant visual imagery, provided tips on feeling relaxed and peaceful, and gave symptom-focused suggestions to reduce pain and nausea. Hypnotized patients used significantly less sedative medication and anesthesia; they also reported less pain, nausea, fatigue, and emotional upset. The researchers estimated that hypnosis translated into a savings of $772.71 per patient, due in large part to the shorter time in the oper­ating room (an average of 10.6 minutes). In another recent study with women getting a large-core needle breast biopsy —a procedure that can be both painful and anxiety producing, since it is usually a test for cancer—hypnosis reduced both pain and anxiety.

Lang doesn’t test her patients to see if they are highly hypnotizable. The more anxious they are about a procedure, she says, the more likely they are to benefit from hypnosis. “A person with a worst-case scenario about what’s going to happen is somebody who has good imagery potential. It takes a very vivid mind to do that.” Studies have shown that phobic people tend to be highly hypnotizable. Lang believes that people slip in and out of trances daily—that everyone has moments of utter absorption when they can’t hear what others are saying to them. “The ability to tune out is practiced throughout the world, particularly in married couples,” she says. Learning to control that absorption offers a way to learn to control pain.

The kidney operation Lang performed that day at Harvard was a good example. The 80-year-old patient came out of her trance at one point—“What is this rubbish about the beach?” she asked—but the doctors soon put her under again with a simple hypnotic suggestion: “Your eyes won’t close until your inner mind gives you permission.”

In February 2007, North Shore Magnetic Imaging Center, a busy private practice in Boston, asked Lang and her associates to train their MRI group in hypnosis. Patients often become claustrophobic while in the tube of an MRI machine, where they are told not to move, and the scans can last 30 to 60 minutes. A panicky patient can be expensive: Repeating a scan because an image is lost when a client shifts in the tube or bolts off the table can cost up to $3,000. Lang trained 15 of the imaging center’s staff in hypnosis, and since then roughly 10 fewer patients each month jump off the table during the exam.

The phenomenon that underlies hypnosis may still be unclear, but patients don’t need to know what causes it as long as it helps them tolerate painful or anxiety-provoking medical procedures. “I think it should be based on data, not on belief,” Spiegel says. “But in the end it doesn’t matter why it works.”